Flame retardant polyamide compositions

Abstract

A glass-reinforced, fire-retardant, arc-track resistant composition characterized in that it contains: (a) at least 35% by weight of a fibre-forming polyamide, (b) 15 to 25% by weight of glass fibres, (c) 16-30% by weight of melamine cyanurate, (d) 2 to 7% by weight of the condensation product of 2 moles of chlorocyclopentadiene and 1 mole of 1,5-cyclooctadiene, and an amount of (e) a fire retardant synergist selected from antimony oxide, iron oxide and stannic oxide, to give a weight ratio of (d) to (e) between 1:1 and 5:1, and wherein the constituents of the composition total 100%.

I claim: 
     
       1. A glass-reinforced, fire retardant, arc-track resistant composition characterised in that it contains: (a) at least 35% by weight of a fibre-forming polyamide,   (b) 15 to 25% by weight of glass fibres,   (c) 16-30% by weight of melamine cyanurate,   (d) 2 to 7%, by weight of the condensation product of 2 moles of chlorocyclopentadiene and 1 mole of cyclooctadiene, and an amount of   (e) antimony oxide, being the sole fire retardant synergist present, to give a weight ratio of (d) to (e) between 1:1 and 5:1 and wherein the constituents of the composition total 100%.     
     
     
       2. A polyamide composition according to claim 1 wherein the concentration of melamine cyanurate is from 17.5 to 27.5% by weight of the composition. 
     
     
       3. A polyamide composition according to either of claims 1 and 2 wherein the concentration of the condensation product (d) is between 2.5 to 5.0% by weight of the composition. 
     
     
       4. A polyamide composition according to any one of claims 1 to 2 wherein the weight ratio of the condensation product (d) to the synergist (e) is between 2:1 and 4:1. 
     
     
       5. A composition according to any one of the claims 1 and 2 wherein the concentration of glass fibre is between 17.5% and 22.5% by weight of the composition.